1. Field of the Invention
The present invention relates to a security device which operates on detection principles--as opposed to armored resistance to PENETRATION--and more particularly to an electrical shield for the protection e.g., of telephone service lines going into and out of a building and/or an associated exterior telephone service or interconnection box.
2. Background of the Invention
Many security systems for homes and commercial buildings use telephone lines to automatically alert police and/or private security forces of attempted intrusions or disturbances. Security for such lines is crucial if the security system is to function as intended. Typically, the telephone lines within a building are connected to the telephone company service lines through an exterior-mounted service or interconnection box. Such telephone service lines and interconnection boxes are subject to tampering, severing, or destruction by intruders or burglars who know to disable the telephone system in order to defeat the building security system.
In general, various devices have been proposed for protection of telephones and telephone lines from vandalism or intrusion. For example, Nix, in U.S. Pat. No. 4,246,451, provides a secure mounting and latching system for a coin telephone mounted on a post in which the telephone and coin box are received in a hardened (i.e., armored) recess closely dimensioned to the size of the telephone housing to frustrate any attempt to pry the telephone and coin box out of the support structure.
Grant, in U.S. Pat. No. 4,673,771, provides a modular, weather-proof terminal box housing designed to be positioned adjacent a large commercial building, the box being partly buried and having a removable panel to provide easy access for changing cables or telephone connections on an interconnection box at the exterior of the building.
Kalfon, in U.S. Pat. No. 4,731,819, describes a device for securing a coin box, such as those associated with pay telephones, to a post anchored to the ground. The installation presents a smooth surface having only a single access to the coin box in order to make the installation vandal-resistant.
Riddle, in U.S. Pat. No. 5,018,185, provides a tamper-resistant pay telephone which uses encasing armor, especially around the cord connecting the handset to the telephone, to make the telephone more vandal-resistant.
Further, some devices have been proposed for protecting exterior telephone lines and interconnection panels. For example, Kraft, in U.S. Pat. No. 5,315,654, and Combs, in U.S. Pat. No. 5,369,548, propose protection devices based upon an armor concept, i.e., in which the physical strength of the protection body is the main deterrent to intrusion. Such protective devices, in addition to being expensive to manufacture and typically requiring professional installation, have proven vulnerable to attack by intruders using high-powered (typically battery-operated) drills or other powered cutting tools.
What is needed is an inexpensive, easy-to-install, protection device which, instead of relying on armor principles to resist penetration presents a "smart" electrical barrier or shield which does not rely on the armor-type protection, but which will respond to an attack on it as if it were an intrusion attempt on the building, and which will automatically signal an alert to police and/or private security forces, for example, by using a preexisting building security system.